Coremakers and related workers in the foundry industry prepare cores that are used in making metal castings. In the founding process, molten metal is poured into a mold that contains a solid central core, usually made of sand or a sand mixture. The metal cools and solidifies. When the core is removed, the desired cavity or shape remains in the metal in place of the core. Cores are made in various sizes and shapes depending upon the desired size and shape of the final casting. There are about 12,400 foundry mold and coremakers employed in the United States. About 125,000 workers are employed as molding, coremaking, and casting machine setters, operators, and tenders.